I was recently in a forum and a member there mentioned that an aperature of a given lens behaves differently on different sensor sizes.


His example was based on the 85L f/1.4. The moment you putthis lenson an APS-C body the lens behaves like a 136mm f/2 lens. Is this correct (I understand the difference between FF and APS-C, it's the f/xx value that's got me wondering between the two)?


So confused!